AutoPlay is the feature that moves playable cards from the tableau to the foundations automatically. (Only those games with foundations have this feature, of course.) This feature can be a great time and effort saver, and I highly recommend its use.

However, there are a couple of things about AutoPlay that you should be aware of. First, in some games (such as FreeCell, Yukon, etc) it is not necessarily a good idea to automatically play every possible card to the foundations. In these games, the best strategy is to keep the foundations pile roughly even with each other (for example, don't play the clubs foundation pile up to 5 or 6 when the ace of hearts hasn't come out yet). Because of this, the AutoPlay feature will NOT play a card to the foundations if it determines that that card might be necessary for play on the tableau. You can, of course, override this if you wish by playing the card to the foundations yourself. But remember, if AutoPlay doesn't move a card that it could move, there's a reason.

Secondly, although in many games it is technically cheating, these games allow you to move a card from the foundations back to the tableau, if you wish. However, if AutoPlay is turned on, the AutoPlay feature will promptly play the card back to the foundation! Therefore, if you ever want to do this you will need to turn AutoPlay off.